Results 21 to 30 of about 650 (183)

Confined Chemistry in Space: Zeolite‐Supported Fe13 Nanoclusters Modulate CS Reactivity

Small Structures, Volume 7, Issue 3, March 2026.
The study explores how an Fe13 cluster confined in chabazite reshapes the reaction of CS and H2 under astrochemical conditions. Confinement promotes C–S bond cleavage over hydrogenation, directing chemistry toward CH4 and H2S formation. Additional CS enables CS2 and C2 species. Microkinetic analysis identifies protoplanetary environments where zeolites
Gerard Pareras, Albert Rimola
wiley   +1 more source

Discovery of Volatile Gas in the Giant Impact Disk Around the 150 Myr Old HD 23514

The Astrophysical Journal Letters
We report the discovery of CO _2 gas emission around HD 23514, an F5V star in the ∼150 Myr old Pleiades cluster, hosting one of the rare giant-impact disks with unique mineralogy dominated by silica dust. We show that the dust feature remains stable over
Kate Y. L. Su, Attila Moór, Chengyan Xie, Ilaria Pascucci, George H. Rieke, Ágnes Kóspál, Mark C. Wyatt, Péter Ábrahám, Luca Matrà, Zoe Roumeliotis, D. J. Wilner   +10 more
doaj   +1 more source

The 12CO gas structures of protoplanetary disks in the Upper Scorpius region

Astronomy & Astrophysics
We present measurements of key protoplanetary disk properties inferred from parametric models of ALMA 12CO spectral line visibilities. We derived gas-disk radii, integrated fluxes, optically thick emission layers, and brightness temperature profiles for ...
Zallio Luigi, Rosotti Giovanni P., Vioque Miguel, Miotello Anna, Andrews Sean M., Manara Carlo F., Carpenter John M., Empey Aaron, Kurtovic Nicolás T., Law Charles J., Longarini Cristiano, Paneque-Carreño Teresa, Teague Richard, Villenave Marion, Yen Hsi-Wei, Zagaria Francesco   +15 more
doaj   +1 more source

Diurnal Variability Modulates Episodic Convection in Hothouse Climates Over Ocean and Swamp‐Like Surface Conditions

Journal of Advances in Modeling Earth Systems, Volume 18, Issue 2, February 2026.
Abstract Hot and moist “hothouse” climates occurred in Earth's past and are expected in Earth's far future climate, driven by increasing solar luminosity. In hothouse climate regimes, precipitation transitions from a quasi‐steady state, as in present‐day tropical convection, to an “episodic deluge” or relaxation‐oscillator (RO) regime where ...
Namrah Habib, Guy Dagan, Nathan Steiger
wiley   +1 more source

Exploring the Effects of Reduced Gravitational Field Impacts on Convective Heat Transfer: A Comprehensive Review

Heat Transfer, Volume 55, Issue 1, Page 764-774, January 2026.
ABSTRACT This review explores the impact of gravitational instability on convective heat transfer, integrating existing research results and theoretical models. Gravitational instability is vital in promoting or hindering convective actions in different systems, such as atmospheric events, ocean currents, and industrial processes.
Hossam A. Nabwey, Muhammad Ashraf, A. M. Rashad, Ali J. Chamkha   +3 more
wiley   +1 more source

Vertical Structure of Gas and Dust in Four Debris Disks

The Astrophysical Journal
We present high-spectral-resolution M -band spectra from iSHELL on NASA’s Infrared Telescope Facility along the line of sight to the debris disk host star HD 32297. We also present a Gemini Planet Imager H -band polarimetric image of the HD 131488 debris
Kadin Worthen, Christine H. Chen, Sean D. Brittain, Cicero X. Lu, Isabel Rebollido, Aoife Brennan, Luca Matrà, Carl Melis, Timoteo Delgado, Aki Roberge, Johan Mazoyer   +10 more
doaj   +1 more source

Fifteen years of “Sonderforschungsbereich” in Heidelberg: Research on circumstellar matter [PDF]

Symposium - International Astronomical Union, 1987
At the end of this year, the Sonderforschungsbereich (Special Collaborative Programme) no. 132 on “Theoretical and Observational Stellar Astronomy” in Heidelberg will terminate after fifteen years. Although 15 years are only 2 1/2 per cent of the age of the University of Heidelberg, which is celebrating its 600 th anniversary this year, they are ...
openaire   +1 more source

Satellites and Small Bodies With ALMA: Insights Into Solar System Formation and Evolution

AGU Advances, Volume 6, Issue 6, December 2025.
Abstract Our understanding of the formation and evolution of planetary systems has made major advances in the past decade. This progress has been driven in large part by the Atacama Large Millimeter/submillimeter Array (ALMA), which has given us an unprecedented view of solar system bodies themselves, and of the structure and chemistry of forming ...
Katherine de Kleer, Michael E. Brown, Martin Cordiner, Richard Teague   +3 more
wiley   +1 more source

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

Detection of a Molecular Hydrogen Envelope around Nova GK Persei

The Astrophysical Journal Letters
The eruption of Nova Persei 1901 (GK Per) occurred 125 yr ago; remarkably, it still holds major surprises. Using data from the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), we find that it has a ...
D. P. K. Banerjee, A. Evans, T. Liimets, C. E. Woodward, T. R. Geballe, V. Joshi, S. Starrfield   +6 more
doaj   +1 more source